1. Field of the Invention
The present invention relates to a thin film coil, a shield part including the same, and a contactless power transmission device having the shield part.
2. Description of the Related Art
Recently, systems for wirelessly, that is, contactlessly, transmitting power in order to charge a secondary cell rechargeable battery embedded in a portable terminal or the like are under development.
Typically, a contactless power transmission device includes a contactless power transmitter transmitting power and a contactless power receiver receiving and storing the transmitted power.
Such contactless power transmission devices transmit and receive power using electromagnetic induction. To this end, the contactless power transmitter and the contactless power receiver respectively include a coil therein.
In the contactless power transmission device according to the related art, this coil is wound in parallel with a bottom surface (that is, an external contact surface). In addition, the coil is fixed to the bottom surface by an adhesive, an adhesive sheet, or the like.
However, in the case of the contactless power transmission device according to the related art, an ordinary wire type coil is used so that the wound coil is overlapped and stacked. Therefore, a problem exists, in that a thickness of the contactless power transmission device increases due to a thickness of the coil, the turns of the coil, and the like.
Therefore, in accordance with the recent trend for thin devices, it is necessary to develop a contactless power transmission device having a reduced thickness.
To this end, a thin film coil, of a type of thin coil other than a wire type coil, is used so as to significantly reduce device thickness, as compared to case of using a wire type coil.
However, in the use of the thin film coil, the thickness of a lead-out portion, a portion thereof which traverses the thin film coil from the central portion of the thin film coil to form an external electrical connection, is inevitably increased.
Accordingly, the thickness of the thickest portion of the thin film coil is determined depending on the thickness of the lead-out portion of the thin film coil.
That is, in order to reduce the overall thickness of the contactless power transmission device, a technique of reducing the thickness of the thickest portion of the thin film coil is required.
The Related Art Document referenced below, relates to a lead-out portion of a coil in an electronic device, capable of being wirelessly charged.
However, unlike the present invention relating to the thin type coil, the coil discussed in the Related Art Document is of wire type and the thickness thereof is significantly thick.
Further, in the case of the wire type coil discussed in the Related Art Document, the lead-out portion may be formed by removing a portion of the shield part and then forming the lead-out portion in the removed portion of the shield part. However, such a scheme is not applicable to the thin type coil disclosed in the present invention.